1. Field of the Invention
This invention relates to a wind turbine of the vertical axis type and more particularly, but not by way of limitation, to a vertical axis wind turbine whose vanes are inclined from the vertical position to provide lift and reduce the load on the turbine's supporting structure.
2. Description of the Prior Art
Until the 15th century, wind power and water power were the only energy sources available. Wind power is abundant in supply and non-polluting, yet it has not been fully utilized. Early commerce used wind power, and Columbus traveled to the New World by wind power. The industrial revolution brought with it dependence on steam and gasoline engines utilizing minerals whose supplies and dwindling and whose use carries with it air and water pollution.
Wind energy is a constantly renewable energy source. Windmills have pumped water for domestic use in outlying areas for hundreds of years. Yet devices heretofore proposed have not proven wholly satisfactory. This may be due in part to mechanical problems associated with windmills, unreliability of wind currents in many regions, and rural electrification efforts of the 1930's.
A variety of wind turbines are known in the art. A Savonius rotor has been designed to reduce drag on its upwind-traveling vane, but it has not completely eliminated the drag effect. An S-type Savonius wind machine remains subject to the Magnus effect, which causes a force on the rotor perpendicular to the wind so that the rotor tends to self-destruct.
A Darrieus rotor, in its several forms, is a vertical axis rotor employing airfoil blades formed in a catenary shape. Unlike the self-starting Savonius rotor, the Darrieus rotor requires an electric motor or a Savonius rotor for starting.
A Giromill, employing symmetrical blades of constant chord, provide blades which are flipped from a positive to a negative orientation at diametrically opposite points. The Giromill wind turbine requires strong winds to start, is difficult to operate at constant RPM and is less efficient than the Darrieus rotor. Large scale installations pose additional difficulties.
A vortex turbine involves a complex structure and considerable amounts of material and labor. Its enormous impact surface is uneconomical to construct and is vulnerable to wind gusts.
A propeller is a horizontal-axis device having good aerodynamic efficiency and high tip speeds, but the propeller requires a tall tower and orientation into the wind.
Power generation from the wind needs new ideas and improvements. As the world's fossil fuel energy sources are depicted, wind can once again play an important role. Improved electrolysis technology permits storage of electrical energy as hydrogen and oxygen, which are then introduced into a fuel cell to produce electrical energy as required.
The simple and uncomplicated structure of the present invention provides a self-starting vertical axis wind turbine which utilizes inclined vanes in a rotor assembly to produce lift on the rotor assembly and reduce friction between the rotor assembly and the rotor assembly's support.